iOS development freelancing advice

Hello everyone, I need some advice about how I can go about becoming a freelancer for iOS and other things down the road. I'm pretty good at iOS Development but the only thing is I have no apps to showcase my skills, Ive been working on a startup the past couple months and I can't show that for obvious reason until it is finished. In the mean time what can I do to start getting clients? Should I make a simple app and put it on the app store as proof, what are some good sites to get clients? and Are there any tips I should know before I start such as how to get paid and taxes?
I'm looking to move soon because and that means I need to make money! Thanks in advanced!